Composite liquid crystal panel

ABSTRACT

A composite liquid crystal panel includes a plurality of liquid crystal panels and a picture display surface. It cuts the border of each liquid crystal panel to a width of only one pixel, then bonding the panels together, installing the picture display surface on the liquid crystal panel, and distributing a portion of light from the normal pixels adjoining the border to the pixels corresponding to the border to resolve the gap problem. Light distribution is accomplished by using a pair of mirrors and a pair of reflecting surfaces to reflect the light of the pixels, so that light may be reflected above the pixels on the border and generate light. Then the pixels on the border and the pixels adjoining the border are redefined to form an image dot. Finally, through redistributing the light, the seams on the border may be completely eliminated.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of application Ser. No. 10/419,779,which was filed on Apr. 22, 2003 now U.S. Pat. No. 6,850,296.

FIELD OF THE INVENTION

The invention relates to a liquid crystal panel and particularly acomposite liquid crystal panel.

BACKGROUND OF THE INVENTION

Three common used TV display systems today are cathode ray tubes (CRT),rear projection, and plasma display panels (PDP). Conventional TVs andfull flat TVs adopt the CRT technology. Although the mature CRTtechnology has the advantages of low price, some shortcomings such assmaller display dimensions, excessive thickness, and high radiationstill exit. The rear projection and PDP TV display systems overcome thehigh radiation by CRT, however, the rear projection TV set has a higherprice. While it is not as thick as the CRT TV set for the same size ofdisplay picture, it still has a substantial thickness. The thin PDP TVset is very with high price, on the other hand, does not popularize thePDP TV sets.

In recent years the composite liquid crystal panel has become adirection many vendors are pursuing in the research of large sizedliquid crystal panels. For instance, the Clarity corporation and thePioneer corporation have introduced composite liquid crystal panels thatconsist of liquid crystal panels. However, on handling the seam, theystill have problems. Specifically, there is a gap on the seam, whichbecomes an eye-sore of the whole liquid crystal screen. Hence the gap isa major bottleneck in the development of the liquid crystal panel atpresent.

In view of the aforesaid issues, the liquid crystal display panel (LCDpanel) is used as the TV set panel. The well-developed and lower pricedpanels of smaller dimensions are not large enough for TV set, while thetechnology of larger dimension LCD panel is still not well developed andvery expansive. For the display systems of smaller size (30 inches orsmaller), there is a growing trend to use the LCD panel to replace theCRT display system. Thus, how to employ the existing and well-developedtechnologies of the LCD panel to produce a larger sized panel is ahighly focused research issue.

SUMMARY OF THE INVENTION

In view of the aforesaid problems in the conventional techniques, theobject of the invention is to provide a composite liquid crystal paneland its manufacturing method. The invention employs LCD panels of asmaller size that can be made at lower prices with mature technologiescurrently available, and a composite technique to produce LCD TVs thathave a larger size, reduced thickness and lower price. Once thetechnology for the large size LCD panel is well developed in the future,the composite technique disclosed in the invention may be used toproduce the LCD TV of even greater size.

The composite liquid crystal panel made according to the techniqueprovided by the invention includes two or more liquid crystal panels anda picture display surface. Each of the liquid crystal panels has aborder for joining to form the composite liquid crystal panel of theinvention. The display pixels corresponding to the border do not havepixel light sources. The picture display surface is located above thecomposite liquid crystal panel to provide a light source for thepicture. There is one or more reflecting surface located above thedisplay pixel corresponding to the border of each liquid crystal panel.The corresponding normal display pixel adjoining the border has one ormore mirror that has both penetrative and reflective functions. Themirror that has both penetrative and reflective functions allows aportion of light of the normal liquid crystal pixel to penetrate andreach the picture display surface, and another portion of light isreflected to the reflecting surface. The reflecting surface thenreflects the light to the picture display surface.

In addition, the picture display surface may be plated with a layer ofsemi-reflective film. The plated film is on the pixels outside theborder and outside the pixels adjoining the border so that illuminationon the liquid crystal panel becomes more even. Or, a color filter may bebonded to the semi-reflection film and the picture display surface tofully mask the border.

In order to prevent the gap from forming on the border, the pixel isredefined. The pixels corresponding to the border of each liquid crystalpanel and the adjoining normal pixels, i.e. p×p pixels, are defined as anew pixel, where p is an integer of 2 or more. Another method forresolving the gap phenomenon on the border is to use an electronic imagecontrol module to control the pixels defined for the border and toprovide these defined pixels with twice as much illumination as otherpixels.

The foregoing, as well as additional objects, features and advantages ofthe invention will be more readily apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the liquid crystal panels of the inventionlaid in a juxtaposed manner.

FIG. 2 is a schematic view of a first embodiment of the composite liquidcrystal panel according to the invention.

FIG. 3 is a schematic view of the redefined pixel for the compositeliquid crystal panel of the invention.

FIG. 4 is a schematic view of a second embodiment of the compositeliquid crystal panel according to the invention.

FIG. 5 is a schematic view of a third embodiment of the composite liquidcrystal panel according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Refer to FIG. 1 for the layout of the liquid crystal panel of theinvention. The invention employs Thin Film Transistor Liquid CrystalDisplay panels (TFT-LCD panels). Each of the TFT-LCD panels has aborder, which is cut to the width of only one pixel (including threedots of Red, Green and Blue). The pixel does not have a pixel lightsource.

A first liquid crystal panel 10 and a second liquid crystal panel 20that have a border cut to the size of one pixel are joined in ajuxtaposed manner to form a composite TFT-LCD panel double the size ofthe individual one. The first pixels 12 and 22 adjoining the border candisplay a picture normally. However, the pixels on the border 11 and 21cannot display pictures in the normal manner. As a result, a gap of twopixels is formed on the displaying picture. As shown in FIG. 1, theformation of the gap is the problem to be overcome by the compositeliquid crystal panel of the invention.

As the border of the liquid crystal panels has already been cut to thesize of one pixel, resolving the problem caused by this one pixel canovercome the gap problem resulting from the absent of a light source.The invention provides a method to eliminate the gap phenomenon on theborder. The method involves adding a picture display surface on thepanel that can distribute light from the pixels adjoining the border,and can display a picture to the pixels on the border that cannotdisplay the picture. Then the pixels corresponding to the border and thenormal pixels adjoining the border can display the same picture. Such amethod requires redefining the pixel. In other words, to alleviate theproblem, the pixel corresponding to the border and the adjoining normalpixel that can display pictures are defined as one image dot.

Because light is redistributed, the resulting illumination is only onehalf of the original. Hence the illumination on the border is notadequate. The invention provides three approaches to resolve thisproblem. The first approach is using an electronic image control moduleto control the light source of the “image dot” on the border to make itsillumination twice as strong than “other image dots”. The secondapproach is using a half reflecting film to bond to the image dots onthe non-border portion so that the image dots on the border have thesame illumination as other image dots. The third approach is anextension of the second approach, but bonds a color filter to completelymask the border.

The method provided by the invention for eliminating the seam of theborder on the composite liquid crystal panel includes the followingsteps: first, providing two or more liquid crystal panels, each with aborder for bonding to each other to form a composite liquid crystalpanel—the displaying pixels corresponding to the border do not have apixel light source; next, providing a picture display surface above thecomposite liquid crystal panel to provide a light source for thepicture—each display pixel corresponding to the border of the liquidcrystal panel has one or more “reflecting surface” located thereabove,and the normal corresponding display pixel adjoining the border has oneor more “mirror surface” with penetrative and reflective functions; thenevery pixel on the border and the normal display pixels adjoining theborder are redefined as image dots, with p×p pixels defined as one imagedot, where p is an integer of 2 or more, so that the light of theadjoining pixel is distributed to the pixel corresponding to the border,thereby eliminating the gap on the border.

Employing the methods mentioned above improve the illumination. Theforegoing methods will be more clearly understood by referring to thefollowing embodiments.

Refer to FIG. 2 for a first embodiment of the composite liquid crystalpanel of the invention. The thickness of the picture display surface isone pixel. The design of the picture display surface on the border, asshown in the drawing, includes: cutting diagonal surfaces of 45° andplating a semi-reflecting film 32 on one diagonal surface and a totalreflecting film 31 on another diagonal surface (with a high reflectingmetal film). The total reflecting film 31 is the actual applicationexample of the “total reflecting surface” previously discussed. Thesemi-reflecting film 32 is the actual application example of the “mirrorsurface” that has penetrative and reflective functions previouslydiscussed. The same is applied for the following embodiments. The totalreflecting film 31 is formed in a right isosceles triangle with thebottom side covering pixels 11 and 21 on the border. I.e. the bottomside has a width of two pixels. The bottom of the semi-reflecting film32 is spaced from the bottom of the total reflecting film 31 at adistance of one pixel. In order to allocate one half of the light of thefirst pixel 12 of the first liquid crystal panel 10 to the pixel 11 onthe border (the same is applied to the first pixel 22 of the secondliquid crystal panel 20 for allocating one half of the light to anotherpixel 12 on the border), the semi-reflecting film 32 and the totalreflecting film 31 are formed at a 45° angle from the liquid crystalpanel. In addition, the reflecting surface of the total reflecting film31 is opposite to the liquid crystal panel to reflect the light from thesemi-reflecting film 32 and to coincide with the direction of theoriginal light beam.

Hence, when the light emitted from the first pixel 12 adjacent to thepixel 11 of the border projects on the surface of the semi-reflectingfilm 32, 50% of the light passes through while another 50% of the lightis reflected. The light passing through continuously travels and passesthrough the picture display surface 30, while the reflected lightreaches the total reflecting film 31 with a high reflective index and isalmost totally reflected, then passes through the picture displaysurface. Similarly, the first pixel 22 adjacent to the pixel 21 of theborder of the second liquid crystal panel behaves in the same way.Therefore, the gap of two pixels on the picture may be eliminated.

Refer to FIG. 3 for redefining the pixel of the composite liquid crystalpanel according to the invention. The drawing illustrates one image dotconsisting of four pixels. In fact, one image dot may also consist ofnine pixels, by the rule of p×p pixels for one image dot, depending onthe size of the liquid crystal panel. The redefined image dot, such asimage dot 13 or 23, includes pixels on the border and the adjoiningpixels. The rest, such as image dots 14 and 24, each consists of fouroriginal pixels.

Through the explanation related to FIGS. 2 and 3, the gap phenomenon onthe border is eliminated by the invention. However, the problem ofillumination is yet to be overcome. The previous discussion has alreadyindicated the methods to resolve this problem. FIG. 4 illustrates two ofthe methods.

First, on the picture display surface above the other pixels on thepanel, plate a layer of semi-reflecting film 40 to make evenillumination for the whole display surface. This is the second method.In order to prevent the border from being visible on the picture displaysurface, a color filter 50 may be bonded to the picture display surfaceto completely mask the border. This is the third method.

Refer to FIG. 5 for a third embodiment of the invention. In thisembodiment, the thickness of the picture display surface 60 is greaterthan one pixel. Structural elements of light distribution for the pixelare the same as the embodiment shown in FIG. 2. However, the totalreflecting mirror 61 and the semi-reflecting mirror 62 do not touch thetop end of the picture display surface, but remain in the picturedisplay surface. This is the only difference. All the rest are the sameas shown in FIG. 2, thus details are omitted here.

Moreover, the semi-reflecting film 40 and the color filter 50 shown inFIG. 4 may also be adopted on the embodiment shown in FIG. 5.Application of the electronic picture control module may also beadopted.

By means of the methods and constructions set forth above, a large sizecomposite liquid crystal panel without the gap phenomenon can be made.

While the preferred embodiments of the invention have been set forth forthe purpose of disclosure, modifications of the disclosed embodiments ofthe invention as well as other embodiments thereof may occur to thoseskilled in the art. Accordingly, the appended claims are intended tocover all embodiments that do not depart from the spirit and scope ofthe invention.

1. A method for eliminating seamless for composite liquid crystalpanels, comprising steps of: providing two or more liquid crystal panelswhich have respectively a border for bonding together with each other toform a composite liquid crystal panel, the border corresponding todisplay pixels which have no light sources; providing a picture displaysurface located above the composite liquid crystal panel to providepicture light sources, each of the display pixels corresponding to theborder having at least one reflecting surface located thereabove, normaldisplay pixels adjoining the border having at least one mirror surfacelocated thereabove equipped with penetrative and reflective functions;and defining an image dot for the pixels corresponding to the border andthe normal pixels adjoining the border by p×p pixels, where p is aninteger of two or more.
 2. The method of claim 1 further including astep for redistributing the light sources to achieve even illuminationby supplying light illumination to the normal pixels adjoining theborder greater a plurality of times than other pixels.
 3. The method ofclaim 2, wherein the step for redistributing the light sources toachieve even illumination is achieved by employing an electronic picturecontrol module.
 4. The method of claim 1 further including a step ofplating a semi-reflecting film on the other pixels outside the borderand outside the pixels adjoining the border to achieve evenillumination.
 5. The method of claim 4, wherein the step of plating asemi-reflecting film is followed by a step of bonding a color filter tocompletely mask the border.